Valve seat grinding tool



Oct. 18, 1938.

Filed Dec. 3l, 1954 Patented Oct. 18, 1938 UNETED STATES PATENT DFFICE VALVE SEAT GRINDING TOOL Application December 31, 1934, Serial No. 759,810

8 Claims.

My invention relates to grinding devices and it has to do more particularly with tools for grind` ing the seats for valves of internal combustion engines.

One of the objects of my invention is to provide an improved tool of the foregoing character, which is of simple and compact construction, which is easy and cheap to manufacture, which may be readily and quickly applied to the valve seat, and which is adapted to quickly grind the valve seat.

Another object is to provide an improved valve seat grinding tool of that character in which an abrading element is centered with respect to the valve seat and is rotatably supported by a pilot firmly secured to the valve guide.

Another object is to provide an improved valve seat grinding tool which is adapted to accurately grind the valve seat without dressing the abrading element from time to time, the abrading element being of an inexpensive character that may be replaced with a minimum of expense when Worn out.

A further object is to provide an improved abrasive mounting for tools of the foregoing character employing an abrading element formed of an abrasive cloth, paper or the like.

Still another object is to provide an improved means for securing the abrading element to a supporting means, which securing means is of a character adapted to yieldably engage and xedly hold the abrading element upon a support and to constantly hold the abrading element taut and in smooth, snug-fitting engagement with the support, notwithstanding the tendency of the abrading element to loosen dueto flexing, stretching or other conditions during operation.

A more specic object is to provide a valve seat grinder embodying a conically-shaped member, detachable or otherwise, adapted to support the abrading element, such support having grooves adapted to receive indentations formed in the abrading element, the abrading element being detachably secured in place by means including fingers that engage in the indentations of the abrading element and hold the abrading element in a predetermined position upon its support.

An additional object is to provide an improved tool of the foregoing character that is adapted for power drive, and which includes driving means capable or" iiexing or yielding axially of the tool to absorb shock and other strains and stresses that may be occasioned by reciprocation of the tool against the valve seat during the grinding operation.

Other objects and advantages having to do with details of construction and arrangement of parts will become obvious as this description progresses and'Y by reference to the drawing wherein,- 5

Figure l is a vertical sectional View of one form of valve grinding tool embodying my invention, the same being shown in operative relation with respect to a valve seat to be ground;

Fig. 2 is a section taken substantially on line 410 2-2 of Fig. 1;

Fig. 3 is a bottom plan view of the tool shown on Fig. l;

Fig. 4 is a detached bottom plan View of the abrading element support of Fig. 1;

Fig. 5 is a side elevational View of the support shown in Fig. 4;

Fig. 6 is a detached bottom plan view of the abrading element of Fig. 1;

Fig. 7 is an elevational View of the springarmed spider for holding the abrading element upon its support;

Fig. 8 is a fragmental view, partially in section, of a modied form of tool embodying my invention; and

Fig. 9 is a top plan view of the structure shown in Fig. 8.

The valve seat grinding tool illustrated in the drawing is of that type embodying a pilot I0 adapted to be firmly secured in the valve guide I I (Fig. l) with its upper end projecting above the cylinder block I2 to rotatably receive a grinding unit that makes abrading contact with the valve seat I 3. Although my invention is particularly Well adapted to a tool of this character, it will be understood that it also has utility in certain instances in connection With tools of that character embodying a pilot secured to the valve grinding unit and adapted to nd rotatable support within the valve guide.

The valve grinding unit shown in the drawing takes the form of a tubular body member I4, the upper end of which is press-tted or otherwise secured within a somewhat enlarged and tubular housing I5. The extent to which the body member Ill may be inserted Within the housing I5 is determined by an annular flange I6 on such body member, which ange also serves as a seat for the upper flat face of an abrasive supporting head Il slidably received upon the lower end of A the body member I4.

The supporting head I'I (Figs. 1, 4 and 5) takes the shape of a truncated cone mounted in inverted position. The tapering sides I8 of this head are disposed at substantially the same angle as the valve seat. The tapering side wall of the head is also provided with a plurality of grooves I9 extending from the upper to the lower' side of the head, the bases 26e of which grooves are at a somewhat steeper pitch than the sidewall I8 of the supporting head (Figs. 1 and 5).

It will be understood that, while I have shown and described the head I1 as detachable, it may be permanently fixed to or may be an integral part of its supporting member without departing from my invention.

The head I1 is adapted to receive an abrading element 20 (Figs. 1, 3 and 6). This element preferably (but not necessarily) takes the form of a flexible material, such as any suitable abrasive cloth, paper or the like. The abrading element is cup-shaped and is shaped to receive the head I1. It is provided with a flat bottom part 2 i, a flared skirt 22, and indentations 23 matched in position with the grooves I9 of the supporting head. In the particular forms shown in the drawing, the indentations 23 are of preferably lesser depth than the head grooves I9 for a purpose which will become obvious hereinafter. The abrading element may be initially preformed to the shape shown in Figs. l and 6 so as to fit upon the head I1 in glove-like fashion with the indentations 23 thereof fitting within the head .grooves to normally hold in position such abrading element upon the head. As will be seen hereinafter, however, the abrading element 2G may initially take the form of a fiat disk having a central opening 24 adapted to receive the lower end of the body member I4, the same being formed to the shape shown in Figs. 1 and 6 by the assembly of the same and its attachment means upon the tool. This will readily be appreciated from the character of the abrading material employed.

The abrading element 2 and its supporting head I1 are secured upon the body member by the following means: After the abrading element has been inserted in place upon the lower end of the body member I4, a spider member 25 (Figs. 1, 3 and 7), having a central opening 26 in its base portion, is next passed over the lower end of the body member. This spider is provided with upstanding and outwardly flaring spring arms 21 that coincide with the supporting head grooves I9 and the indentations 23 of the abrading element. The pitch of the spider arms 21 is, preferably, slightly less than the pitch of the bases of the abrading element indentations and the bases of the head grooves I9. The spring arms, due to their particular arrangement, and in the case of a preformed abrading element, enter the indentations 23 of the abrading element so that, as the spider 25 is forced home to the position shown in Fig. 1, the spring arms 21 thereof yieldably and tensionally engage the abrading element and press the same inwardly upon the head I1 thereby seating and holding the same in snug-glovelike engagement with the head I1. In case the abrading element is not preformed, the spider arms 21 force the contacted portions of the abrading element into the head grooves I9 as the spider 25 is forced home to the position of Fig. 1, thereby forming the abrading element to the shape of Fig. 6 and securing the same in the manner above stated.

The spider 25, the abrading element 2Q and head I1 are secured in place by a detachable nut 28 that engages a screw-threaded end portion of the body member I4. This nut may be used to force the spider 25 and abrading element to their operative positions of Fig. 1 and to, at the same time, clampingly wedge the head I1 between the flange I6 and the spider 25 so that the parts are locked against relative rotation in the rotational movement of the tool.

With the foregoing arrangement, the abrading element is initially applied and held in place upon the head I1 in a smooth fitting relation and without Wrinkling or other distortion that might tend to prevent proper valve grinding op eration. Additionally, since the spring arms 21 of the spider yieldably and tensionally engage the abrading element, they at all times tend to hold the abrading element taut upon the head I1, maintaining this condition notwithstanding any tendency of the abrading element to stretch and loosen during thegrinding operation. It will be noted in Fig. 1 that the head grooves I9 are of sufficient depth to permit the spring arms 21 to carry out this take-up function.

It is desirable in a tool of this character to avoid heating up of the external and exposed parts of the tool due to the heat generated by the contact between the abrasive and the valve seat. To this end, I form the body member, the head I1 and the nut 28 of some suitable material (preferably, but not necessarily, steel or the like) and the housing I5 of aluminum. The aluminum housing is also provided with a plurality of circumferential fins 29 that tend to further the foregoing purpose in a manner well understood.

It is desirable that tools of this character be rotatively driven by power means. It is also desirable that the power driving connection with the tool be of a character permitting proper engagement of the abrading element with the valve l seat notwithstanding disalignment between the drive and the tool. It has also been found that, in tools of this character, very desirable grinding results may be obtained by reciprocating the rotating valve grinding unit to intermittently engage the valve seat during the grinding operation. In this way the grindings and cuttings resulting from the grinding operation are freed and removed so that the cutting action will take place more rapidly and the abrading element will perform its grinding function properly.

To the foregoing ends my invention contemplates the provision of a flexible drive shaft releasably connectible to the housing I5 and formed of a material adapted to flex or yield in axial r direction when the grinding unit is reciprocated during operation to thereby absorb the shock, etc., occasioned by such reciprocatory movement. More particularly, the upper end of the housing I5 is provided with a tubular sleeve 30 press-fitted or otherwise xedly secured therein. The inner wall of this sleeve is so shaped that it provides a hexagonal socket, the bottom of which is determined by a cross pin 3I. The sleeve socket 3D is adapted to detachably receive the hexagonal head 32 of a metallic member having a stem portion 33 inserted within and secured to the lower end of a drive shaft 34 by a pin 35.

The shaft 34 is of tubular from and I have found that excellent results may be obtained by making the s-ame from a rubber material, the section of which may be strengthened somewhat, if desired, by the inclusion therein of a suitable fabric material such as indicated at 36 in Figs. 1 and 2. The thickness of the shaft wall and the character of the rubber material employed are such as to permit the shaft to yieldv toward the grinding unit without impairing its ability to drive. The length of the shaft I4 may vary according to the particular conditions ot use,although I have found that a rather short shaft will well serve the purpose.

The upper end of shaft 34 receives a driving spindle 31 secured thereto by a cross pin 38. This spindle is adapted to be directly connected to the drive means (not shown). 'Ihe opposite ends of the shaft 34 are strengthened by metallic supporting shields or ferrules 39 that receive the ends of pins 35 and 38 and render the ends of the shaft sufficiently rigid to properly perform the driving function.

From the foregoing it will be seen that the shaft 34 will tend to cushion and absorb shock caused by reciprocation of the tool against the valve seat during rotation of the tool and it will also serve as a flexible, univers-al-like drive connection between the power drive means (not shown) and the grinding unit. The thickness of the wall of shaft 34 and the character of the material employed `are such as to insure the foregoing.

The shaft 34 is releasably latched to the upper end of the housing l5 by the structure shown in Fig. 1. More particularly, the driving head 32 is provided with a cross passage 40 in which is received a spring 4| Balls 42 mounted within the passage 40 at the opposite ends of the spring 4I, the latter constantly tending to press such balls outwardly. Outward displacement of balls 42 is prevented by the slightly reduced size of the outer ends of passage 40, although a substantial part of the balls is permitted to project from the ends of the passage 40. When the head 32 is fully inserted within the socket member 30 the balls snap into an annul-ar groove 43 formed in the socket member and thereby frictionally resist detachment of the shaft from the housing l5. By applying suitable outward pressure to the shaft 34 detachment may be readily accomplished, as will be well understood.

Structures embodying my invention may take various forms, one modication, for example, being shown in Figs. 8 and 9. This form of structure is similar to that shown in the previous iigures except that cam-operated fingers or arms are employed instead of the spring fingers 21 of the spider 25. More particularly, the body member 44, like the body member I4, carries an abrasive supporting head 45 having grooves 46. A ring member 41 is mounted between the body flange 48 and the top of the head 45, and those portions of the ring ext-ending over the tops of the grooves 46 are provided with openings 49 that receive the upper ends of abrasiveattachment arms 5U. 'I'he ring openings 49 and the upper ends of the arms 5D are so relatively shaped that the arms may take a hinging movement but such arms will not be displaced by longitudinal pressure thereon in their operative positions. The arcuate shape of the upper ends of the arms 50 accomplish this purpose, while permitting ready attachment of the arms by rocking the same outwardly and downwardly.

The abrading element 5| employed in connection with the structure of Figs. 8 and 9 may be like that of Fig. 6, the indentations thereof being adapted to receive the arms 5U which are cammed inwardly to draw the abrading element taut upon the head 45. The lower end of the body 44 receives a funnel-shaped member having a bottom portion 52 with an opening adapted to receive the body 44 and an upstanding and outwardly flaring skirt portion 53 that is adapted to `engage the lower offset end portions 54 of the arms 5U. 'I'he parts are held in operative position by a nut 55 screwed on to the lower end of the body 44 which nut, when screwed upon the body, forces the camming member upwardly so that its skirt 53 engages the cam-like arm ends 54 and cams the arms 50 inwardly to secure the abrading element as shown in Fig. 8. If desired, the camming member or the camming skirt portion 53 thereof may constitute a part of the nut 55 without departing from my invention.

I believe that the objects and advantages of my invention as hereinabove set forth, as well as the oper-ation of the same, will be readily understood from the foregoing description. Also, it is to be understood that while I have shown only two forms of structure embodying my invention, other changes in details and arrangement o-f parts may be made without departing from the spirit and scope of my invention as defined by the claims that follow.

I claim:

1. In a valve seat body member having seat to be ground, and having comparatively deep longitudinal grooves therein, an abrading member fitted upon said head and having indentations adapted to enter said grooves, an abrasive holding member mounted on said body below said head and having arms that project into said indentations and hold said element in uniform engagement with said head side wall, and another member engaged with the threaded end of said body for holding said abrading element and first member in operative position relative to said head.

2. In a valve seat grinding tool, a rotatable body member having a lower threaded end, an abrasive supporting head on said body adjacent the threaded end and having a side Wall tapered substantially complementally to the taper of the seat to be ground, and having comparatively deep longitudinal grooves therein extending substantially from one end of the head to the other end, an abrading element fitted upon said head and having indentations of size and form adapted to enter said grooves vsubstantially throughout of said body for holding said abrading element and holding member in tive to said head.

3. In a valve seat grinding tool, a rotatable body member, an abrasive supporting head on one substantially complementally to the valve seat to be ground, and also having a substantially flat bottom surface with grooves extending therefrom to the top surface of said head, an abrading element having a bottom portion with an opening to receive said body and a skirt portion adapted to iit upon said head side wall, said skirt portion having indentations received within said grooves and said element bottom portion being adapted to seat against the bottom surface of said head, an abrasive securing member mounted upon said. body beneath said abrading element and having arms adapted to be received within said indensaid abrading element tations and of such size and shape that they press upon said head side wall when said member is seated against the bottom portion of said abrading element, and means adjustably and detachably mounted on said body beneath said securing member for moving and holding the latter in operative position against said abrading element.

4. In a valve seat grinding tool, a rotatable body member, an abrasive supporting head on one end of said body and having a side Wall tapered substantially complementally to the valve seat to be ground, and also having a substantially flat bottom surface with grooves extending therefrom to the top surface of said head, a cup-shaped abrading element having a bottom portion adapted to seat against the bottom surface of said head and provided with an opening to receive said body and a skirt portion adapted to iit upon said head side wall, said skirt portion having indentations received within said grooves, an abrasive securing member mounted upon said body beneath said abrading element and having a part adapted to seat against the bottom portion of said element and provided with arms adapted to be received within said indentations and to hold said abrading element upon said head side wall when said member is seated against the bottom portion of said abrading element, and means adjustably and detachably mounted on said body beneath said member for moving and holding the latter in operative position against said abrading element and for clamping said abrading element and member in an operative position.

5. In a tool of the class described, a rotatable body, an abrasive supporting head on said body having a side wall tapered substantially complementally to the taper of the valve seats to be ground and provided with longitudinally extending grooves, a cup-shaped abrading element having a skirt portion adapted to fit upon the side wall of said head and provided with indentations adapted to t within said grooves, and means for securing said abrading element upon said head which includes arm members adapted to extend within and substantially throughout said indentations, an element at the top of said head for swingably supporting said arms, and a. cam member adjacent the bottom of said head and carried by said body and adapted in axial adjustment movement thereof to engage and cam said arms into said indentations to draw said abrading element circumerentially upon said head and to maintain it in taut and snug-fit relation thereon.

6. In a tool of the class described, an abrasive supporting head on said body having a side wall tapered substantially complementally to the taper of the valve seat to be ground and provided with longitudinally extending grooves, a cup-shaped abrading element to fit upon the side Wall of said head and provided with indentations adapted to flt within said grooves, means for securing said abrading element upon said head which includes a plurality of arms adapted to fit within said indentations and swingably supported at their upper ends by means at the top of said head, said arms having their lower ends formed to provide camming elements, a cam member carried by said body adjustable axially thereon, said camming member having a flared camming surface within which the cam-ends of said arms are received and which act upon said cam-ends of the arms to swing said arms inwardly into said indentations and to thereby draw said abrading element into smooth snug-fit engagement with said head.

7. In a Valve seat grinding tool, a rotatable body member, an abrasive supporting head on one end of said bodxT and having longitudinally extending and comparatively deep grooves therein, an abrading element mounted upon said head and having indentations of lesser depth than said head grooves adapted to project into said head grooves, means beneath said abrading element and engaging said element within said indentations for securely holding the abrading element upon said head, said body having a part extending beneath said means, and a retaining member detachably mounted on said body part beneath said means for holding the tion against the abrading element.

8. In a valve seat grinding tool, a rotatable body, an abrasive supporting head member through which one end of said body projects, said head having a side wall with longitudinally extending grooves therein and of a Ashape adapted to t the valve seat to be ground, an abrading element tted upon and shaped similarly to said head and having indentations therein received within said head grooves, means carried by the projecting end of said body and projecting into said indentations for positively securing said abrasive element to said head and for drawing and holding said element taut upon said head, and a retaining member detachably mounted on the projecting end Vof said body for holding said abrasive-securing means in operative position against the abrading element.

JOHN E. GALLIVAN.

having a skirt portion adapted i latter in operative posi- 

